There are three major areas of investigation: the first of these has to do with a study of the effect of anti-idiotypic antibodies in EAE. Lewis rats will be immunized with encephalitogenic peptides 68-85 and 68-88 from guinea pig myelin basic protein. Affinity chromatography will be used to obtain purified anti-peptide antibodies and these antibodies will then be used to immunize rabbits or Lewis rats for production of anti-idiotypic antibodies. The anti-idiotypic antisera will be assayed for 1) the ability to inhibit binding of radiolabelled antigen to the rat antibody used for immunization and to anti-peptide antibodies from a large number of other rats, b) specificity for VH or VL regions of the antipeptide antibody used for immunization, and c) the ability to alter the function of T-lymphocytes involved in the manisfestations of EAE in vivo and in vitro. The second major area of investigation has to do with a systematic and comprehensive study of structure, metabolism, and function of myelin basic protein so as to achieve a better understanding of the role of myelin in normal and pathological states. These studies will include the following: a) the isolation and characterization of the primary sequence and physical chemical properties of the large rat basic proteins, b) to isolate and characterize myelin basic protein dimers from CNA of several species of different ages, c) to measure the turnover of myelin proteins in rat brain fractionated by sucrose density gradient zone centrifugation, d) to study the synthesis and degradation of myelin proteins in rat brain. The third major area of investigation is an attempt to show a specific interaction between some component of normal and/or multiple sclerosis CNS tissue and MS cerebrospinal fluid IgG. These investigations will include the following: 1) the purification of CSF IgG by affinity chromatography using Sepharose linked to rabbit anti-human IgG, 2) the fractionation of normal and MS brain tissue by continuous gradient ultracentrifugation into soluble, myelin, organelle, and particulate fractions, 3) to test the reactivity of purified MS GSF IgG with the various brain fractions by standard immunochemical techniques, including immunoelectrophoresis, radioimmunoelectrophoresis, gel filtration and detection of immune complexes by ultracentrifugation. In addition, studies are designed around the possibility that preformed comp (Text Truncated - Exceeds Capacity)